Light-absorbing water-permeable colloid layer containing an oxonol dye



April 19, 1966 LIGHT-ABSORBING WATER-PERMEABLE COLLOID J. BAILEY3,247,127

LAYER CONTAINING AN OXONOL DYE Filed March 27, 1961 6 E LATIN CONTAININGBIS [I-CARBOXWWETHYb HEXAHYDRO -3 "n- OCTYL-2,4-,6*TRIOXO 5-P'YRIMIDINE) PENTAMETH IN OXONOL Fig.1

LIEHT SENSITIVE SILVER HALIDE EMULSION LIGHT SENSITIVE SILVER HALIDEEMULSION /*GELATIN commons BIS E-BUTYL-S-CARBOXY'METHYLHEMHYDRO-ZfiB-TRIOXO s- F'YRIMIDINE) PENTAMETHINOXONQL SUPF-ORTLIGHT SENSITIVE K. SILVER HALIDE EMULSION SUPPORT GELATIN CONTAININGe|s[|-eum-3- CAR BOXYMETHYLHEXAHYDRO 2 3,6-

TRIOXO 5"PYR|MIDINE) PENTAMETHINONOXOL Joseph/Bailey IN VEN TOR.

BY 4. W/M

ATIDRNEY (A AGEN'J United States Patent 3,247,127 LIGHT-ABSORBINGWATER-PERMEABLE COL- LOID LAYER CONTAINING AN OXONOL DYE Joseph Bailey,Wealdstone, Harrow, England, assignor to Eastman Kodak Company,Rochester, N.Y., a corporation of New Jersey Filed Mar. 27, 1961, Ser.No. 98,709 Claims priority, application Great Britain, Apr. 14, 1960,13,379/ 60 9 Claims. (Cl. 252300) This invention relates to new dyes andmore particularly to photographic elements containing these dyes inlight-screening layers.

It is known that photographic elements require for many purposes to havelight-screening substances incorporated therein. Such a light-screeningsubstance may be in a layer overlying a light-sensitive emulsion oroverlying two or more light-sensitive emulsions; or it may be in alight-sensitive emulsion for the purpose of modifying a light record insuch emulsion or for protecting an overlying light-sensitive emulsion oremulsions from the action of light of wavelengths absorbed by suchlightscreening substance; or it may be in a layer not containing alight-sensitive substance but arranged between two light-sensitiveemulsions; or it may be in a layer serving as a backing on an elementhaving one or more light-sensitive emulsions (for example to reducehalation) In particular, light-screening substances are often required(a) in overcoatings upon photographic elements to protect thelight-sensitive emulsion or emulsions from the action of light which itis not desired to record, e.g., ultraviolet light in the case of stillor moving pictures, especially color pictures, (b) in layers arrangedbetween differentially color sensitized emulsions, e.g., to protect redand green sensitive emulsions from the action of blue light, and (c) inbackings forming the socalled antihalation layers on either side of atransparent support carrying the light-sensitive emulsion or emulsions.

In most cases and especially where the element contains a colorsensitized emulsion or color sensitized emulsions, it is particularlydesirable to employ lightscreening substances which do not affect thegeneral sensitivity or the color sensitivity of light-sensitiveemulsions with which they may come into contact. It is also particularlydesirable to employ light-screening substances which do notsubstantially diffuse from the layers or coatings in which they areincorporated, either during the manufacture of the element or on storingit or in photographically processing it. Finally it is generallynecessary to employ light-screening substances which can readily berendered ineifective, i.e., decolorized or. destroyed and removed priorto or during or after photographic processing. For many purpose it isparticularly convenient to employ light-screening substances which arerendered ineffective by one of the photographic baths employed inprocessing the element after exposure, such as a photographic developingbath or fixing bath. The decoloration or destruction of thelight-screening dye will hereinafter be referred to as bleaching.

Numerous substances have been employed as lightscreening materials forthe purposes indicated above. Among the dyes used are the oxonol dyes.Oxonol dyes known in the past have not absorbed light of the wavelengthdesired. Previously known oxonol dye-mordant combinations, however,which are sufiiciently nonwandering to use in layers in contact withemulsion layers,

are bleached only with difiiculty or not at all during normal processingof the film. Those known combinations which bleach more easily are notsufficiently nonwandering so the dye migrates to the emulsion layerswith a consequent deleterious elfect upon the sensitometric propertiesof the film. In some instances where the lightscreening dye has beenmordanted to make it sufficiently nonwandering, the dye does not bleachsatisfactorily in the processing baths and it has been necessary toremove the light-screening layer itself from the photographic element toeliminate the unwanted residual dye.

It is therefore an object of my invention to provide a new class ofsymmetrical oxonol dyes which have their maximum absorption of light atthe wavelength desired.

Another object is to provide new symmetrical acid oxonol dyes which arereadily mordanted in light-screening layers so that they will notdiffuse into adjacent emulsion layers and dyes which are readilybleached by conventional processing solutions without removing thelightscreening layer containing them.

Another object is to provide a new class of light-screen ing filterlayers which are valuable for use in photographic elements asinterlayers between two sensitive silver halide emulsion layers, betweenthe support and a sensitive silver halide emulsion layer, as a layerover a sensitive silver halide layer or as an antihalation layer behindthe support.

Another object is to provide a method for preparing new symmetricaloxonol dyes.

Still other objects will become apparent from the followingspecification and claims.

I have found that the above objects are accomplished by usingsymmetrical oxonol dyes represented by the following formula:

wherein Z represents the nonmetallic atoms necessary to complete al-carboxyalkyl-3hydrocarbon substitutedhexahydro-2,4,6-trioxo-5-pyrimidine nucleus and n is an integer of: from1 to 3.

Particularly advantageous dyes of my invention may be represented by thefollowing formula:

wherein R is a carboxyalkyl group in which the carboxy substituent isattached to an alkyl group having from 1 to 2 carbon atoms such asmethyl and ethyl; R is a member selected from the class consisting of analkyl group having from 1 to 8 carbon atoms, such as methyl, benzyl,ethyl, propyl, isopropyl, butyl, secondary butyl, tertiary butyl, hexyl,octyl, cyclohexyl, etc., an aryl group, such as phenyl, Z-methylphenyl,Z-methoxyphenyl, 2,4-dimethylphenyl, etc.; n is an integer of from 1 to3; X is a hydrogen atom or an alkyl group having from 1 to 4 carbonatoms such as methyl, ethyl, propyl, butyl, etc., such that not morethan one X is an alkyl group.

My dyes are valuable for use in photographic lightsensitive materialsemploying one or more sensitive silver halide layers. The dyes can beused to make light-screening layers including antihalation layers withor without dyes of other classes and can be incorporated readily incolloidal binders used for forming such layers. They are especiallyuseful in gelatin layers lying adjacent to silver halide layers, sincethe dyes can be mordanted with organic polymeric substances to formexcellent nonwandering characteristics in gelatin While the dyes can bereadily bleached without the need for removing the layers containingthem. Bleaching of the dyes occurs when the layer is treated withalkaline solutions containing sodium sulfite such as photographicdeveloping solutions.

My dyes can be m-ordanted in layers coated in contact withlight-sensitive silver halide emulsion layers since the dyes have verygood stability at the pH of most sensitive silver halide emulsions(about 6.3) and have little or no undesirable effect on the silverhalide. Consequently, the dyes may be used as light-screening dyes inlayers coated directly on top of sensitive silver halide emulsion layersor between two sensitive silver halide emulsion layers or between thesupport and a sensitive silver halide emulsion layer or on the back ofthe support as an antihalation layer.

Representative dyes of my invention and their preparation areillustrated by the following examples which are not intended to limit myinvention.

Example 1 .Bis 1 -n-butyl-3-carb0xymethy lhexa'lzydro-2,4,6-trix0-5-pyrimidine pentamethinoxonol HO 0 C C Hz1-n-butyl-3-carboxymethylbarbituric acid (3.6 grams) glutaconic aldehydedianilide hydrochloride (2.13 grams), ethanol (30 cc.) and triethylamine(8.4 cc.) were heated on the steam bath for 20 minutes. The dye solutionwas chilled and acidified with concentrated hydrochloric acid (12 cc.)and the solution was poured into water (750 cc.). The precipitated dyewas collected, washed with Water and dried. The product which weighed 3grams (73%) melted at 88 C.

The dye in water had an absorption maximum at 590 m Analysis fOrC25H30N4010:

| C l N Cald 55. 0% 5. 10. 2% Found. 55. 3% 6. 2% 10. 05%

Example 2Bis(1 -carb0xymethylhexahydro-3-n-0ctyl- 2,4,6tri0x0-5-pyrimidine) pentamethinoxo nol Analysis for C 3H N4O10I CaldFound Example 3 .Bis(1 -carb0xymetlzyl-3-cycl0hexylhexa'hyrim-2,4, 6-triox0-5 pyrimidine pentamefh inoxonol HOOC-(IJHZ H(|) ?H2-COOH NCO CNOC\ /C=CHOH=CHCH=CHO\ CO N-oo CtHn CoHn Prepared similarly to Example 1using a proportional amount of 1-carboxyrnethyl-3-cyclohexylbarbituricacid instead of 1-n-butyl-3-car-boxymethylbarbituric acid. The dye wasobtained in yield, it melted at and had an absorption maximum in ethanolat 592 m Analysis for C19H3N401QI Calcd-N, Found- N, 9.2%.

Example 4 .Bz's( 1 -carb0xymethy lhexalzydr0-3-phenyl-2,4,6-fri0x0-5-pyrimidine pent'amethinoxonol This dye was preparedsimilarly to Example 1 using a proportional amount of1-carboxymethyl-3-phenylbarbituric acid instead of1-n-butyl-3-carboxyrnethylbarbituric acid. The dye was obtained in 63%yield, it melted at and had an absorption maximum in ethanol at 591 mAnalysis for C H N O Cald 9. 6% Found Example5.Bis(1-carb0xymetlzylhexahydr0-3-n-octyl- 2,4,6-trioxo-5-pyrimidine)-3-methylpentamethinoxonol This dye was prepared similarly to Example 2using 1- anilino-S-anilo-3-methyl-1,3-pentadiene HBr in place ofglutaconicaldehyde dianilide HCl. The dye was obtained in 86% yield, ithad an absorption maximum in ethanol at 614 m Example 6 .Bis (.1-carb0xymethy lhexahydr0-3-n-0cty 2,4,6 -tri0x0-5 pyrimidine) trimethinoxonol HOOCLCHZ HO CH2.COOH NC 0 as CO C=CHCH=CHC CO NC O BC-N CaHir$51117 5 Analysis for C H44N O Z C H N Cald 58. 9% 7. 8. 9% Found 60. 0%7. 15% 9.

Example 7.Bis(1-n-butyl-3-carb0xymethylhexahydro-2,4,6-trioxo-5-pyrimidine) trimethinoxo-nol Prepared similarly toExample 6 using a proportional amount ofl-n-butyl-3-carboxymethylbarbituric acid in place of1-carboxymethyl-3-n-octylbarbituric acid. The dye was obtained in 60%yield, melted at 66 and had an absorption maximum ethanol at 493 mp.

Analysis for C H N O H 0:

Cald 51. 3% 5. 6% 10. 4% Found- 51. 0% 5. 9% 10. 1%

Example8.Bis(1-carb0xymethyl-3-cycl0hexyllzexahydr0-2,4,6-trioxo-S-pyrimidine)trimethz'noxono-l Prepared similarly to Example 6 using a proportionalamount of l-carboxyrnethyl-Ii-cyclohexylbarbituric acid in place of1-carboxymethyl-3-n-octylbarbituric acid. The dye was obtained in 63%yield, melted at 170 and had an absorption maximum in ethanol at 494 mAnalysis for C27H32N4010: CaldN, 9.

Example 9.--Bis(l -carboxymethy lhexahydro-S-n-octyl-2,4,6-triox0-5-pyrimidine) methinoxonoll-carboxymethyl-B-n-octylbarbituric acid (6 g.), ethyl orthofor-mate (3cc.), pyridine (15 cc.) were heated under reflux for 30 minutes. Thereaction mixture was cooled, diluted with water (100 cc.), acidifiedwith concentrated hydrochloric acid, cooled and the product collected byfiltration. It was dried and recrystallized from ethyl acetate. The dyeweighed 2.5 g. (41%), melted at 173 C. and had an absorption'maximum inmethanol at 415 m Analysis for C2gH42N4010:

C H N iliif.IIIIIIIIIIIIIIIIIIII 5533;; 32353 31 i3;

The following are further examples of compounds according to the presentinvention.

Found ExampleJ0.Bis(1-tertiarybutyl-S-carboxymethflhexahydro-2,4,6-tri0x0-5-pyrimidine)penfamethinoxonol Example 1 1 .--Bis(1 -carb0xymethyl-3-n-hexylhexahydr0 2,4,6-tri0x0-5pyrimidine) pen-tamethinoxonol Example 12.Bis(1-benzyl-3-carb0xymethylhexahydro- 2,4,6-triox0-5-pyrimidinepentamethinoxonol Example 13.Bis(1-carboxymethyllzexahydr0-3-0-metlzoxyphenyl-2,4,6-tri0x0-5-pyrimidine)pentamethinoxonol Example14.Bz's(1-tertimybutyl-3-carboxymethylhexahydr0-2,4,6-tri0x0-5-pyrimidl'ne) trimet'hinoxonol Example15.Bz's(I-z:arboxymezhyl-3-n-hexylhexalzyalro 2,4,6-trioxo-5-pyrimidine)trimeth inoxonol Example 16.Bis( 1 -benzyl-3-carb0xymetlzylhexalzydro-2,4,6-trioxo-S-pyrimidine) trimethinoxon'ol Example17.Bis(1-carb0xymethylhexahydr0-3-0-methoxyphenyl-2,4,6-trioxo-S-pyrimidine)trimethinoxonol Example 18.Bis(1 -n-butyl-3-carb oxymethylhexalzydro-2,4,6 -tri0x0-5 -pyrimidine) methinoxonol Example 19.Bis(1-tertiarybutyl-3-carb0xymethylhexahydro-2,4,6-trioxo-S-pyrimidine)methinoxonol The intermediates used in preparing my dyes weresynthesized according to the following procedures which are typical andwill illustrate the methods used to prepare intermediates for other dyesof my invention.

N ETHOXYCARBON'Y LMETHYLN -N-OCTYLUREA C2H5OOC'CH2'NH'CONHC3H17Ethoxycarbonylmethyl isocyanate (Ann. 1948, 5 62, 76) (17.5 grams) inbenzene (25 cc.) was treated with noctylamine (17.5 grams) in benzene(25 cc.). There was a temperature rise on mixing and the solution wasmaintained at room temperature overnight. The solvent was pound using aproportional amount of n-butylamine in place of n-octylamine. It yield)was obtained as very low melting colourless needles.

Analysis for C H N O Cald-N, 13.9%. N, 13.3%.

N-ETHOXYCARBONYLMETHYL-N-PHENYLUREA C2H5OOC CH2 NH C5H5 It was obtainedsimilarly to the above using a propor tional amount of aniline in placeof n-octylamine. It

(72% yield) was obtained as colourless needles, M.P. 108109 C.

N-CYCLOHEXYL-N-ETHOXYCARBONYLUREA C H OOC-CH 'NH-CONH 0 H It wasobtained similarly to the above using a proportional amount ofcyclohexylamine in place of n-octylaminep It (70% yield) was obtained aslong colourless needles, M.P. 121122.

Other intermediates according to the invention include:

Found-- N-tertiarybutyl-N-ethoxycarbonylrnethylureaN-ethoxycarbonylmethyl-N-n-hexylureaN-benzyl-N'-ethoxycarbonylmethylureaN-ethoxycarbonylmethyl-N'-o-methoxyphenylurea Analysis for C H25O5N2:

1 O i H N Oald 58. 9% 8. 8. 6% Found. 57. 8. 1% 8. 35%

l-n-BUTYL-3 ETHOXYCARBONYLMETHYL- BARBITURIC ACID Prepared similarly tothe above intermediate. It was obtained in 52% yield as a colourlessviscous oil, B.P. 161163/O.2 mm.

1 ETHOXYCARBONYLMETHYL-3-PHENYL- BARBITURJC ACID Prepared similarly tothe above intermediate. It was obtained in 63% yield as a pale yellowviscous oil, B.P. 216218/O.5 mm.

l-CYCLOHEXYL-S-ETH OXYCARBONYLMETHYL- BARBITURIC ACID I Cs n Preparedsimilarly to the above intermediate. It was obtained in 83% yield as apale yellow viscous oil, B1. l78-l8()/0.2 mm.

Other intermediates according to the invention include:

l-tertiarybutyl-3-ethoxycarbonylmethylbarbituric acid1-ethoxycarbonylmethyl-3-n-hexylbarbituric acid1-benzyl-3-ethoxycarbonylmethylbarbituric .acid

l-ethoxycarbonylmethyl 3 o methoxyphenylbarbituric acidl-CARBOXYMETHYL-3-n-OCTYLBARBITURIC ACID Noo CH2 NC6l-ethoxyc'arbonylmethyl-3-octylbarbituric acid (16 grams) was treatedwith aqueous sodium hydroxide (10 cc., 40%) in water (40 cc.). Thesolution was heated 011 the steam bath for 4 hours. Then the reactionmixture was chilled and acidified with concentrated hydrochloric acid.The separated oil was extracted with benzene. The benzene solution wasconcentrated and solid product was obtained by warming the residual gumwith petroleum ether (B.P. 4060). The product was collected andrecrystallized from petroleum ether (B.P. -100 C.) as colourless shinyplates. The product weighed 9 grams (62%) and melted at ll7.5l18.5 C.

Analysis for C H O N Cald 5s. 4% 7. 4% 9. 4% Found. 56.3% 7. 6% 9. 2%

1-n-BUTYL-3-CARBOXYMETHYLBARBITURIC ACID HOOOEH:

N-CQ 0o CH2 N-CO To a solution of potassium hydroxide (6.65 grams) inmethanol (75 cc.) was added 1-n-butyl-3-ethoxycarbonylmethylbarbituricacid (13.5 grams). The mixture was maintained overnight at roomtemperature when the solid potassium salt of the product precipitated.It was collected by filtration and washed with methanol. It wasdissolved in water and the solution acidified with hydrochloric acid.The separated oil was extracted with benzene. The benzene solution wasconcentrated and the residual oil purified by dissolution in ethylacetate and treating the solution by the dropwise addition of petroluemeither (B.P. 6080) until the product began to precipitate. Afterchilling, the colourless crystals were collected. The product weighed 4grams (33%) and melted at 7375 C.

Analysis for C H O N o I H l N Cald 49. 6% 5 8% 11.6% Found 50. 0% 6 0%11.35%

1CARBOXYMETHYL3PHENYLBARBITURIC ACID H O C CH2 NCg Prepared in a similarway to l-n-butyl-S-carboxymethylbarbituric acid. It was obtained in 43%yield as colourless crystals, M.P. 100.

Analysis for C H N O i C H N Cald 55. 0% 3. 8% 10. 7% Found 54. 3% 4. 5%10. 6%

1-CARBOXYMETHYL-3-CYCLOHEXYLBARB I- TURIC ACID Anaylsis for C H N O l Gl H l N Cald 53. 7% 6. 0% 10. 4% Found. 53. 6% 5. 85% 10.7%

Other intermediates according to the invention include:

1-tertiarybutyl-3=carboxymell1ylbarbituric acidl-carboxymethyl-B-n-hexylbanbituric acid1-bcnzyl-3-carboxyrnethylbanbituric acidl-carboxymethyl-3-o-methoxyphenylbarbituric acid The light-screeninglayers of my invention are prepared by coating on the photognaphicelement or on its support, by methods well known in the art, a watersolution of the dye, a hydrophilic colloid binder and a coating aid suchas saponin. In addition to these materials it is advantageous t add abasic mordant to this solution to render the acid dye nonwandering. Formost purposes it is desirable to add agents to harden the colloidalbinder material so that the light-screening layer will remain intact inthe photographic element during and following the processing operation.The pH of the coating solution is adjusted when necessary to a levelthat is compatible with the light-sensitive emulsion layer by the usualmethods.

The proportions of dye, colloidal binder, mordant, hardener, coating aidused in making my light-screening layers may be varied over wide rangesand will depend upon the specific requirements of the photographicelement being produced. The methods used to determine the optimumcomposition are well known in the art and need not be described here.

The light-sensitive layer or layers and the light-screen ing layer orlayers of the photographic element may be coated on any suitable supportmaterial used in photography such as cellulose nitrate, celluloseacetate, synthetic resin, paper, etc. i

Hydrophilic colloidal materials used as binders include collodion, gumarabic, cellulose ester derivatives such as alkyl esters of carboxylatedcellulose, hydroxy ethyl cellulose, carboxy methyl hyd-roxy ethylcellulose, synthetic l 0 resins, such as the amphoteric copolymersdescribed by Cl-avier et al. in US. Patent 2,949,442, issued August 16,1960, polyvinyl alcohol, and others well known in the art. Theabove-mentioned amphoteric copolymers are made by polymerizing themonomer having the formula:

CH CR C O OH wherein R represents an atom of hydrogen or a methyl group,and a salt of a compound having the general formula:

CH =(IJ R wherein R has the above-mentioned meaning, such as anallylamine salt. These monomers can further be polymerized with a thirdunsaturated monomer in an amount of 0 to 20% of the total monomer used,such as an ethylene monomer that is copolymerizable with the twoprincipal monomers. The third monomer may contain neither a basic groupnor an acid group and may, for example, be vinyl acetate, vinylchloride, acrylonitrile, methacrylonitrile, styrene, acrylates,methacrylates, acrylamide, methacrylamide, etc. Examples of thesepolymeric gelatin substitutes are copolymers of allylamine andmethacrylic acid; copolymers of allylamine, acrylic acid and acrylamide;hydrolyzed copolyrners of allylamine, methacrylic acid and vinylacetate; copolymers of allylamine, acrylic acid and styrene; thecopolymer of allylamine, methacrylic acid and acrylonitrile; etc.

My dyes are generally added to the water-permeable colloidal binder inwater solution. In some instances it may be advantageous to form analkali metal salt of the dye by dissolving the dye in a dilute aqueousalkali metal carbonate solution, for example. Usually a coating aid,such as saponin, is added to the dyed colloidal suspension beforecoating it as a layer on the photographic element. The dyes areadvantageously mordanted with a suitable basic mord'ant added to thecolloidal suspension before coating.

Basic mordants that may be used include the basic mordants described byMinsk in US. 2382, 156, issued April 14, 1959, prepared by condensing apolyvinyloxo-compound such as a polyacrolein, a poly-'y-methylacrolein,a polyvinyl alkyl ketone, such as polyvinyl methyl ketone, polyvinylethyl ketone, polyvinyl propyl ketone, polyvinyl butyl ketone, etc., orcertain copolymers containing acrolein, methacrolein, or said vinylalkyl ketone components, for example, 1 to 1 molar ratio copolymers ofthese components with styrene or alkyl methacrylates wherein the alkylgroup contains from 1 to 4 carbon atoms, such as methyl, ethyl, propyl,or butyl methacrylates in the proportions from about .25 to 5 parts byweight of the said polymeric oXo-cornpound with one part by weight of anaminoguanidine compound such as aminoguanidine bicarbonate,aminoguanidine acetate, aminoguanidine butynate, etc.; the reactionprodnets of polyvinyl-sulfonates with C-aminopyridines of Reynolds etal. US. 2,768,078, issued October 23, 1956, prepared by reacting alkyland aryl polyvinyl sulfonates prepared as described in our patents US.2,531,468 and US. 2,531,469, both dated November 28, 1950, undercontrolled conditions with C-aminopyridines or alkyl group substitutedC-aminopyridines such as 2-aminopyridine, 4-aminopyridine, theaminopicolines such as 2- amino-3-methy-lpyridine,2-amino4-methylpyi-ridine, 2- amino-S-methylpyridine,2-amino-6-methylpyridine and corresponding 4-aminomethyl derivativeswhich react in this reaction in exactly the same way,2-arnino-6-ethylpyridine, 2-amino-6-bntylpyridine,2-amino-6-amylpyridine, etc., the various aminolutidines such as, forexample, 4-am-ino-2,6-dimethylpyridine and the various aminocollidinessuch as, for example, 2-amino-3-ethyl-4-methylpyridine, etc.; thedialkylaminoalkyl esters or dialky1 aminoalkylamino amides, e.g., suchas those described by Carroll et al. U.S. Patent 2,675,316, issued April13, 1954, prepared by reacting addition polymers containing carboxylgroups with a basic dialkylamino compound, for example, N-dialkyl amineethyl esters of polymers or copolymers containing carboxyl groups; theaddition type polymers containing periodically occurring quaternarygroups of Sprague et al. U.S. 2,548,564, issued April 10, 1951,including quaternary ammonium salts of vinyl substituted azines such asvinylpyridine and its homologs such as vinylquinoline, vinylacridine,and vinyl derivatives of other six-membered heterocyclic ring compoundscontaining hydrogen atoms. These addition polymers include2-vinylpyridine polymer metho-p-toluenesulfonate, 4-vinylpyridinepolymer metho-p-toluenesulfonate.

Hardening materials that may be used to advantage include such hardeningagents as formaldehyde; a halogensubstit-uted aliphatic acid such asmucobromic acid as described in White, U.S. Patent 2,080,019, issued May11, 1937; a compound having a plurality of acid anhydride groups such as7,8-diphenylbicyclo (2,2,2)-7-octene- 2,3,5,6-tetra-carboxylicdianhydride, or a dicarboxylic or a disulfonic acid chloride such asterephthaloyl chloride or naphthalene-1,5-disulfonyl chloride asdescribed in Allen and Carroll, U.S. Patents 2,725,294 and 2,725,295,both issued November 29, 1955; a cyclic 1,2-diketone such ascyclopentane-LZ-dione as described in Allen and Byers, U.S. Patent2,725,305, issued November 29, 1955; 1a bisester iof methane-sulfonicacid such as l,2-di(meth- |anesulfonoxy)-ethane as described in Allenand Laakso, U.S. Patent 2,726,162, issued December 6, 1955;1,3-dihydroxymethylbenzimidazol-Z, one as described in July, Knott andPollak, U.S. Patent 2,732,316, issued January 24, 1956; a dia-ldehyde ora sodium bisulfite derivative thereof, the aldehyde groups of which areseparated by 2-3 carbon atoms, such as fl-methyl glutaraldehydebis-sodium bisulfite as described in Allen and Burness, U.S. patentapplication Serial No. 556,031, filed December 29, 1955, and nowabandoned; a bis-aziridine carboxamide such as itrimet hylenebis(1-aziridine oarboxarnide) as described in Allen and Webster, U.S.Patent 2,950,197, issued August 23, 1960; or 2,3-dihydroxydioxane asdescribed in Jeffreys, U.S. Patent 2,870,013, issued January 20, 1959.

The photographic element utilizing my light-screening layers havelight-sensitive emulsion layers containing silver chloride, silverbromide, silver chlorobromide, silver iodide, silver bromoiodide, silverchlorobromoiodide, etc., as the light-sensitive material. Anylight-sensitive silver halide emulsion layers may be used in thesephotographic elements. The silver halide emulsion may be sensitized byany of the sensitizers commonly used to produce the desiredsensitometric characteristics.

My invention is further illustrated by the following examples describingthe preparation of photographic elements containing my light-screeninglayers.

Example 20 An aqueous solution was made up which contained 4.54 g. ofgelatin, .91 g. of poly(or-methyl allyl-N-guanidylketimine), .153 g. ofsaponin, and .302 g. of bis(1- butyl 3 carboxymethylhexahydro 2,4,6trioxo 5- pyrimidine) pentamethinoxonol to a total weight of 150 g. at apH of 6.1. This solution was coated on clear cellulose acetate filmsupport at 4.6 g. per sq. ft. The resulting coating was overcoated witha fine-grained silver chlorobromide emulsion with panchromaticsensitization at a silver coverage at 257 milligrams of silver per sq.ft. A control was coated on clear support. These film samples wereexposed in an intensity scale sensitometer, then developed for 6 minutesin a developer having the composition:

G. p-Methylaminophenol sulfate 2.2 Sodium sulfite (desiccated) 72.0Hydroquinone 8.0

G. Sodium carbonate (anhydrous) 48.0 Potassium bromide 4.0

Water to 1 liter.

fixed for 10 minutes in a fixing bath having the formula:

Sodium thios-ulfate g 240.0 Sodium sulfite (desiccated) g 15.0 Aceticacid, 28% cc 48.0 Boric acid crystals g 7.5 Potassium alum g 150.0

Water to 1 liter.

Washed and dried.

The following tables gives the halation latitude determined for thesefilm samples as the increase over normal required in log E exposure togive a halation density of 0:1 in the center of a 0.008 inch wideunexposed line.

Halation Latitude Clear Blue Green Red Control 78 51 71 53 Film sampleprovided with lightscreening layer 1.67 .86 1.74 2.36

Example 21 0.5 gram of the dye of Example 2 was dissolved in 1% aqueoussodium carbonate and added to a 5% gelatin solution containing 0.5 grampolyvinylpyridinium methop-toluenesulfonate. The pH of the solution wasadjusted to 6.5. This dyed gelatin solution was then coated on top of asensitive silver halide emulsion of the kind used for Xray photographyat the rate of 25.5 mg. of dye per square foot. Two such coatedmaterials were made from exactly the same emulsion and dyed gelatinsolution and measurements made on the products are shown below as A andB, along with the measurements on the same prodnet but omitting the dyefrom the gelatin.

The three products were exposed, developed in the developer of Example17 for 4 minutes and fixed in a hypo solution of Example 17 in the usualway and washed. The dyed layers were completely bleached by thistreatment. In the following table, the column headed Safety Factor, arerelative measurements of the inverse of the effective sensitivity of thematerial when exposed to the red component of the light transmitted by aWratten 68 Darkroom Safelight, which contains an amber coloured filtertransmitting light in the range of 570 to 700 m with a maximumtransmission at a wavelength of 595 III/1.. The Safety Factor wascalculated as the antilogarithm of the inverse of the logarithm of thespeed measured as the exposure required to give a density of 0.2 abovethe fog density. 7

Thus the Safety Factor to Wratten 6B Safelight for the photographicelement protected with my light-screening layer was about twice as highas it was for the control.

The accompanying drawing containing FIGS. 1, 2 and 13 3 still furtherillustrates my invention. FIGS. 1, 2, and 3 represent greatly enlargedcross-sectional views of lightsensitive photographic elements containingmy light-absorbing water-permeable colloid layers.

FIG. 1 shows light-screening layer 10 consisting of gelatin containingbis(l-carboxymethylhexahydro-3-noctyl-2,4,6-trioxo-S-pyrimidine)pentamethinoxonolmordanted with polyvinylpyridinium metho-p-toluenesulfonate coated overlight-sensitive silver halide emulsion layer 11 which is coated onsupport 12.

FIG. 2 shows light-sensitive silver halide emulsion layer 13 coated overlight-screening layer 14 consisting of gelatin containingbis(1-butyl-3-carboxymethylhexahydro-2,4,6-trioxo-5-pyrimidine)pentamethinoxonol mordanted with a-methylallyl-N-guanidylketimine coated over support 15.

FIG. 3 shows light-sensitive silver halide emulsion layer 16 coated onsupport 17 bearing antihalation backing layer 18 consisting of gelatincontainingbis(1-butyl-3-carboxymethylhexahydro-2,4,6-trioxopyrimidine)pentamethinoxonolmordanted with a-methyl allyl-N-guanidylketimine.

The symmetrical, acid oxonol dyes of my invention are valuable forpreparing light-screening layers .for making light-sensitivephotographic elements containing silver halide emulsion layers. Thelight-screening layers containing my dyes are used to advantage eitherover the light-sensitive silver halide emulsion layers, between thelight-sensitive silver halide emulsion layer and the support, betweentwo difierent light-sensitive layers, or as an antihalation backinglayer. My dyes are characterized by having maximum light absorption atdesirable wavelengths. They are further characterized by being readilymordanted with basic mordants so that they will not wander intolight-sensitive silver halide emulsion layers coated directly in contactwith them and yet they are readily bleached in the light-screening layerby conventional processing solutions which contain. sodium sulfite.Furthermore, my dyes are characterized by having very good stability atthe pH of most sensitive silver halide emulsions (about 6.3) and havelittle or no undesirable eifect on the sensitivity of the silver halideemulsion layer even when they are used in direct contact with them.

The invention has been described in detail with particular reference topreferred embodiments thereof but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention as described hereinabove and as defined in the appendedclaims.

I claim:

1. A light-absorbing water-permeable colloid layer containing alight-absorbing dye as a light-screening sub stance having the formula:

wherein R is a carboxyalkyl group in which the alkyl group has from 1 to2 carbon atoms; R is a member se- 1 4 lected from the class consistingof an alkyl group having from 1 to 8 carbon atoms and an aryl group; nis an integer of from 1 to 3; X is a member selected from the classconsisting of a hydrogen atom and an alkyl group having from 1 to 4carbon atoms such that not more than one X is an alkyl group, in anamount sufiicient to impart light screening properties to the saidcolloid layer.

2. The light-absorbing layer of claim 1 containing a basic mordant forthe said dye.

3. The light-absorbing layer of claim 1 containing poly- (ct-methylallyl-N-guanidylketirnine) as a basic mordant for said dye.

4. The light-absorbing layer of claim 1 containing polyvinylpyridiniummetho-p-toluenesulfonate as a basic mordant for said dye.

5. A light-absorbing water-permeable gelatin layer containing thelight-absorbing dye bis(1-n-butyl-3-carboxymethylhexahydro-2,4,6-trioxo-5 pyrimidiue)pentamethinoxonol as alight-screening substance, in an amount sufficient to impart lightscreening properties to the said gelatin layer.

6. A light-absorbing water-permeable gelatin layer containing thelight-absorbing dye bis(l-carboxymethylhexahydro-3 noctyl-2,4,6-trioxo-5-pyrimidine)pentamethinoxonol as light-screeningsubstance, in an amount sufficient to impart light screening propertiesto the said gelatin layer.

7. A light-absorbing water-permeable gelatin layer containing thelight-absorbing dye bis(l-carboxymethylhexahydro 3phenyl-2,4,6-trioxo-5-pyrimidine)pentamethinoxonol as a light-screeningsubstance, in an amount suflicient to impart light screening propertiesto the said gelatin layer.

8. A light-absorbing water-permeable gelatin layer containing thelight-absorbing dye bis(1-n-butyl-3-carboxymethylhexahydro 2,4,6trioxo-S-pyn'midnefirimethinoxonol as a light-screening substance, in anamount sulficient to impart light screening properties to the saidgelatin layer.

9. A light-absorbing water-permeable gelatin layer containing thelight-absorbing dye bis(1-carboxymethyl-3- cyclohexylhexahydro 2,4, 6-trioxo 5 pyrimidine)trimethinoxonol as a light-screening substance, inan amount sufiicient to impart light screening properties to the saidgelatin layer.

References Cited by the Examiner UNITED STATES PATENTS 2,345,193 3/1944Gaspar 260-2402 2,533,206 12/1950 Dent et a1. 260240.2 2,533,472 12/1950Keyes et a1. 9684 2,534,654 12/1950 Barnes 252300 2,611,698 9/1952Jennen 9684 2,614,940 10/1952 Freyermuth et a1. 252300 JULIUS GREENWALD,Primary Examiner. PHILIP E. MANGAN, Examiner.

W. C. GILLIS, JR., R. D. LOVERING,

Assistant Examiners.

1. A LIGHT-ABSORBING WATER-PERMEABLE COLLOID LAYER CONTAINING ALIGHT-ABSORBING DYE AS A LIGHT-SCREENING SUBSTANCE HAVING FORMULA: